1. Field of the Invention
The present invention generally relates to a memory, and more particularly, to a voltage monitoring technique of a memory.
2. Description of Related Art
An electronic device usually needs a plurality of power voltages with different levels, so that the electronic device is often equipped with a charge pump circuit to use an available power voltage for producing the required power voltages with different levels. In terms of a flash memory, for example, the word line voltage therein is produced by a charge pump circuit.
The word line voltage required by a flash memory for accessing data must remain within an appropriate range. When the word line voltage is excessive, the reliability of the flash memory may adversely affected; when the word line voltage is too low, the access speed of the flash memory may have adversely affected.
Accordingly, a testing engineer must use a testing probe to monitor the word line voltage so as to make sure whether or not the word line voltage is abnormal to render the flash memory unstable or slow access speed. Since the word line voltage is varied with the operation of a flash memory; therefore, to correctly judge whether or not the word line voltage is normal during the operation of the memory, the testing engineer needs to keep the memory running while directly measuring the word line voltage with the testing probe. Therefore, obviously the above-mentioned conventional procedure is inconvenient.